Doctrine - PHP5 Database ORM

Doctrine is an ORM (object relational mapper) for PHP 5.2.x+ that sits on top of
a powerful DBAL (database abstraction layer). One of its key features is the
ability to optionally write database queries in an OO (object oriented)
SQL-dialect called DQL inspired by Hibernates HQL. This provides developers with
a powerful alternative to SQL that maintains a maximum of flexibility without
requiring needless code duplication.